1. Field of the Invention
The present invention relates to an electronic timepiece, such as a wrist watch, with a bearing detector and, more particularly, to an electronic watch with a bearing detector for performing of starting and ending operations bearing measurement.
2. Description of the Prior Art
A conventional electronic wrist watch with a bearing detector, as shown, for example comprise by a block diagram in FIG. 7, comprise a microprocessor (CPU) 10, a memory (ROM) 11 for storing a system program, processing program and the like for the CPU 10, a memory (RAM) 12 for storing processing data and the like, an oscillation circuit 13 for providing a clock signal to the CPU 10, a display circuit 14 driven by the CPU 10 for performing time display, bearing measurement value display and the like, a bearing detection circuit 15 controlled by the CPU 10 for performing bearing measurement, a frequency-dividing circuit 16 for frequency-dividing an oscillation frequency of the oscillation circuit 13 and generating a 1-Hz timing signal, a push button 17 for starting bearing measurement and an interrupt circuit 18.
Although the electronic wrist watch with a bearing detector is usually utilized by wearing on the arm, a wearer has been required to press a measurement push button 17 when starting bearing measurement. The wearer fully understands that measurement with the electronic wrist watch with a bearing detector positioned in a horizontal state is suited for bearing measurement. However, there are often cases that the push button 17 is pressed in a state that the electronic wrist watch with an bearing detector is not horizontal but inclined. If bearing measurement is made by the electronic wrist watch with a bearing detector in such an inclined state, there is a problem that the measurement accuracy is decreased.
The problem that the present invention is to solve is to improve bearing measurement accuracy by automatically starting bearing measurement when an electronic wrist watch with a bearing detector becomes is positioned a horizontal state.